The officials cited Moran's ability to win the swing county, understanding of suburban communities and history of working with the past two Democratic governors, Timothy M. Kaine and Mark R. Warner.

"Loudoun is the key to victory in Virginia, and Loudoun Democrats know Brian Moran can win here," said Kelly Burk (Leesburg), a member of the Board of Supervisors. "We have to make sure that the Democratic nominee can win decisively in Northern Virginia and the suburbs. That's what it takes to win."

The officials represent about two-thirds of Loudoun's elected Democrats, including members of the Board of Supervisors, School Board and Leesburg Town Council, the Leesburg mayor and state legislators.

"It is an honor to receive the support of so many of Virginia's leaders," Moran said in a news conference at the Old Loudoun County Courthouse. "Here in Loudoun, Democrats know what it takes to win -- a Virginia leader with a record of winning races and partnering with Mark Warner and Tim Kaine."

Moran, chairman of the House Democratic caucus, faces state Sen. R. Creigh Deeds (Bath) in the primary. Deeds narrowly lost a bid for attorney general in 2005, to Robert F. McDonnell, the presumptive GOP nominee for governor next year. Former Democratic National Committee Chairman Terry McAuliffe filed paperwork Monday to launch a potential candidacy for governor and will make a decision in January.

"It's clear that Northern Virginia will be one of many battleground areas in this election, and Senator Deeds is doing as well, if not better, than his two opponents from inside the Beltway," said Peter Jackson, a Deeds spokesman. Jackson cited support from Northern Virginians, including Sen. Mary Margaret Whipple (Arlington), chairwoman of the Senate Democratic caucus, Fairfax County chief prosecutor Raymond F. Morrogh and his predecessor, Robert F. Horan Jr.

Mo Elleithee, a consultant to McAuliffe, called the endorsements "terrific" for Moran. "It's really good to see Democrats engaged in the race at this early stage, and that's a great thing ultimately for the party," he said.